A METHOD FOR MASS PRODUCING SPORES OF THE MICROSPORIDIAN NOSEMA FUMIFERANAE IN ITS HOST, THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1976 ◽  
Vol 108 (4) ◽  
pp. 383-386 ◽  
Author(s):  
G. G. Wilson
Keyword(s):  
Mass Production ◽  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Spruce Budworm ◽  
Fourth Instar ◽  
Spore Concentration ◽  
Spore Yield

AbstractThe mass production of Nosema fumiferanae spores using second, third, and fourth instar larvae of Choristoneura fumiferana is described. In general, second instar larvae inoculated with 2 × 105 spores per millilitre of suspension resulted in a maximum spore yield of 1.3 × 108 spores per larva. A spore concentration of 2 × 107 reduced larval weights and increased larval mortality.

LONG TERM STUDY OF THE EFFECTIVENESS OF AERIAL APPLICATION OF BACILLUS THURINGIENSIS – ACEPHATE COMBINATIONS AGAINST THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1977 ◽  
Vol 109 (9) ◽  
pp. 1239-1248 ◽  
Author(s):  
O. N. Morris
Keyword(s):  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
Population Densities ◽  
Long Term Study

AbstractBacillus thuringiensis (Dipel® 36B) mixed with a sublethal concentration of acephate (Orthene®) (O, S-dimethyl acetylphosphoramidothioate), an organophosphorous insecticide, was applied at 2.35–14 l./ha to white spruce (Picea glauca) and balsam fir (Abies balsamea) trees infested with spruce budworm, Choristoneura fumiferana (Clem.). The treatment rate was 20 Billion International Units of B. thuringiensis (B.t.) activity with or without 42 g of active ingredient of acephate/ha.The ground deposit of the standard Dipel wettable powder formulation was 12% of emitted volume compared with 21–32% for the Dipel 36B flowable. The viability of B.t. spores was drastically reduced after 1 day of weathering but a high level of biological activity by the spore–crystal complex persisted for up to 20 days post-spray due probably to crystal activity.The addition of about 10% of the recommended operational rate of acephate to the B.t. suspension increased larval mortality by 34% when applied at 4.7 l./ha. Reductions in budworm populations were 97–99% in B.t. + acephate plots and 86–90% in B.t. alone plots.Plots with moderate budworm densities of up to 27 larvae/100 buds on white spruce and 36/100 on balsam fir were satisfactorily protected from excessive defoliation in the year of spray by B.t. with or without acephate. Plots with higher population densities were not satisfactorily protected based on the branch sample examination but aerial color photographs indicated good protection to the top third of the trees. Population declines were greater and defoliation and oviposition were lower in the treated plots than in the untreated checks 1 year later without further treatment. Two years later the larval population densities in all plots were low but the density was twice as high in the untreated check as in the treated plots, indicating long term suppression by the treatments. Defoliation was negligible in all plots.The treatments had no deleterious effect on spruce budworm parasitism. The data indicate that the integrated approach using Bacillus thuringiensis – chemical pesticide combinations is a viable alternative to the use of chemical pesticides alone in spruce budworm control. Large scale testing is now warranted.

EFFECT OF TEMPERATURE ON THE PATHOGENESIS OF BACILLUS THURINGIENSIS BERLINER IN LARVAE OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA CLEM. (LEPIDOPTERA: TORTRICIDAE)

1994 ◽  
Vol 126 (4) ◽  
pp. 1061-1065 ◽  
Author(s):  
Kees van Frankenhuyzen
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacterial Growth ◽  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Lethal Dose ◽  
Spruce Budworm ◽  
Effect Of Temperature ◽  
Vegetative Cells ◽  
Time Required ◽  
Peak Abundance

AbstractThe relationship between temperature and pathogenesis of Bacillus thuringiensis Berliner var. kurstaki in infected larvae of the eastern spruce budworm, Choristoneura fumiferana Clem., was investigated to determine if more rapid death of larvae with an increase in temperature could be accounted for by enhanced bacterial growth. Cumulative mortality of larvae force-fed with a lethal dose of HD-1-S-1980 peaked within 2 days at 25 °C, 3 days at 19 °C, 7 days at 16 °C, and 21 days at 13 °C. The progress of bacterial growth in the larvae was followed from spore germination to cell lysis, and was completed within 4 days at 25 °C, 6 days at 22 °C, 12 days at 19 °C, 14 days at 16 °C, and > 28 days at 13 °C. Peak abundance of vegetative cells in the larvae was observed after 1 day at 25 °C, 2 days at 22 °C, 3 days at 19 °C, 7 days at 16 °C, and 21 days at 13 °C, and thus coincided almost exactly with the time required for maximum larval mortality. This correlation suggests that the observed effect of temperature on progression of larval mortality was due to its effect on the proliferation of vegetative cells in the infected larvae, and that bacterial septicemia makes an important contribution to death.

Second Diapause in Spruce Budworm from Eastern Canada

1961 ◽  
Vol 93 (7) ◽  
pp. 594-602 ◽  
Author(s):  
George T. Harvey
Keyword(s):  
British Columbia ◽  
Experimental Analysis ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Fourth Instar ◽  
Eastern Canada ◽  
Low Incidence ◽  
One Year ◽  
Storage Times ◽  
Second Period

In eastern Canada larvae of the spruce budworm, Choristoneura fumiferana (Clem.), complete their development in one year, undergoing only one period of winter diapause in the second instar, whereas in certain parts of British Columbia, at high altitudes, two years are normally required for development, the larvae spending a second period of winter diapause in the fourth instar (3, 9). Among laboratory-reared eastern budworm there are a few individuals that enter a similar second diapause (7). The low incidence and somewhat irregular occurrence of this second diapause in eastern budworm, even in laboratory rearings, have hitherto made detailed studies almost impossible, but unusual storage times and treatments used recently in rearing experiments had the unexpected effect of increasing the incidence of this tvpe of behaviour to a level where experimental analysis became possible. This paper describes these larvae and their behaviour; an account of the effects of various conditions upon the incidence of second diapause will be presented later.

CONTACT AND RESIDUAL EFFECT OF LOW-VOLUME DOSAGES OF PHOSPHAMIDON TO CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE) ON TWO SPECIES OF CONIFERS

1972 ◽  
Vol 104 (7) ◽  
pp. 1051-1054
Author(s):  
J. F. Stewart ◽  
N. R. Brown
Keyword(s):  
Statistical Difference ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Residual Effect ◽  
Spruce Budworm ◽  
Picea Rubens ◽  
Fourth Instar ◽  
Red Spruce ◽  
Balsam Fir ◽  
Low Volume

AbstractA series of low-volume spray treatments were conducted to study the contact and residual effect of two concentrations of the insecticide phosphamidon to fourth instar spruce budworm, Choristoneura fumiferana (Clem.), on balsam fir, Abies balsamea (L.) Mill, and red spruce, Picea rubens Sarg. Treatment of sprayed larvae on sprayed trees, unsprayed larvae on sprayed trees, and sprayed larvae on unsprayed trees, resulted in two principal conclusions: (a) Higher concentrations of phosphamidon (1% versus 0.5% active) accelerated mortality in all instances and (b) no statistical difference (P = 0.1%) was found in the final mortalities between treatments in which only the foliage was treated and where both larvae and foliage were treated with phosphamidon.

scholarly journals Bacillus Thuringiensis: a Logical Weapon for Spruce Budworm Control

1978 ◽  
Vol 54 (6) ◽  
pp. 309-312 ◽  
Author(s):  
W.A. Smirnoff
Keyword(s):  
Bacillus Thuringiensis ◽  
Environmental Variables ◽  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Field Tests ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Insect Density ◽  
Different Levels ◽  
Methods Of Application

Action of Bacillus thuringiensis (B.t.) on spruce budworm, Choristoneura fumiferana Clem., was found to be attributable to septicemia with some enterotoxicosis. Development of a compact economical B.t. formulation, with addition of the enzyme chitinase, increased its efficiency by accelerating larval mortality. Between 1971 and 1975 field tests were conducted in balsam fir stands with different levels of insect density to select the best formulation and methods of application and to identify the major influencing environmental variables. Variability in the results prior to 1975 is attributable to difficulties with calibration of spray systems. With accurate calibration in 1976 and 1977, good results in terms of larval mortality and foliage protection were obtained, thus confirming the value of B.t. for control of spruce budworm.

FOLIAR AND SYSTEMIC APPLICATIONS OF NEEM SEED EXTRACT FOR CONTROL OF SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (CLEM.) (LEPIDOPTERA: TORTRICIDAE), INFESTING BLACK AND WHITE SPRUCE SEED ORCHARDS

1997 ◽  
Vol 129 (4) ◽  
pp. 645-655 ◽  
Author(s):  
Kevin W. Wanner ◽  
Blair V. Helson ◽  
Barry C. Kostyk
Keyword(s):  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Spruce Budworm ◽  
Weather Conditions ◽  
Urban Environments ◽  
Seed Extract ◽  
Neem Seed ◽  
Adverse Weather ◽  
Neem Seed Extract

AbstractNeem seed extract (20, 60, and 180 ppm azadirachtin) applied to the crowns of black spruce trees immediately prior to female reproductive bud flush, resulted in high mortality of early instar spruce budworm larvae. Dose-dependent reductions of 40–93%, as compared with check trees, were observed 2 and 4.5 weeks after treatment. Seed cone protection from grazing damage, however, was moderate; at 60 ppm azadirachtin, the incidence of cone grazing was reduced 29%, and the proportion of severely grazed cones reduced 39%, as compared with check trees. Larval mortality and bud damage observed in the laboratory corroborated field results. High toxicity to second-instar larvae, and performance during adverse weather conditions, supports the potential of neem seed extract for control of spruce budworm defoliation. However, both laboratory and field results indicate that feeding occurs before the effects of neem seed extract manifest, resulting in moderate protection of cones. Whereas foliage can tolerate low levels of feeding, female strobili are damaged significantly. Excellent protection of foliage was achieved from systemic injections of neem seed extract to white and black spruce trees (1.5 g azadirachtin/tree). Neem seed extract, formulated for systemic application, could provide a botanical alternative for control of forest pests in urban environments.

Multiple effects of tebufenozide on the survival and performance of the spruce budworm (Lepidoptera: Tortricidae)

2016 ◽  
Vol 149 (2) ◽  
pp. 227-240 ◽  
Author(s):  
Kees van Frankenhuyzen ◽  
Jacques Régnière
Keyword(s):  
Mating Success ◽  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Pupal Stage ◽  
Spruce Budworm ◽  
Larval Survival ◽  
Host Trees ◽  
Population Reduction ◽  
High Larval Mortality ◽  
And Performance

AbstractAerial application of Mimic® 2LV to rising outbreak populations of the spruce budworm (Choristoneura fumiferana (Clemens); Lepidoptera: Tortricidae) in Québec, Canada, resulted in high levels of population reduction at spray deposits of 0.5–1.2 μg tebufenozide/g of foliage. Application to potted host trees in outdoor enclosures followed by bioassays revealed multiple effects on spruce budworm survival and recruitment. Chronic (14-day) exposure of late-instars to treated foliage reduced larval survival and also pupal survival, mating success, and fecundity, depending on the product concentration applied. Treatments that produced foliar deposits of ~ 0.5–1.5 μg tebufenozide/g caused high larval mortality. Exposure to deposits of ~ 0.15–0.5 μg/g caused delayed mortality during the pupal stage and reduced the mating success of survivors, while exposure to ~ 0.07–0.15 μg/g reduced the fecundity of mated females. Sublethal exposure did not affect the progeny of survivors, either in egg hatch, survival during diapause, or survival and performance after diapause. Reduced survival during late-larval and pupal stages combined with lower recruitment as a result of reduced mating success and fecundity are likely to play a role in the suppression of Mimic®-treated spruce budworm populations in the years following treatment.

A dosing technique and the effects of sub-lethal doses of Nosema fumiferanae (Microsporida) on its host the spruce budworm, Choristoneura fumiferana

Parasitology ◽  
1983 ◽  
Vol 87 (3) ◽  
pp. 371-376 ◽  
Author(s):  
G. G. Wilson
Keyword(s):  
Adult Female ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Spore Concentration ◽  
Microsporidian Parasite ◽  
Male And Female ◽  
Female Longevity ◽  
Living Adult ◽  
Lethal Doses ◽  
Significant Mortality

SummaryVarious dosages of the microsporidian parasite, Nosema fumiferanae were fed to 12-day-old larvae of Choristoneura fumiferana using a previously undescribed bioassay capsule. A spore dose of 3 × 104 resulted in 92% infection and a significant reduction in pupal weights, adult female longevity and a mean spore concentration of 1·5 × 107/living adult. Significant mortality (68%, combined larvae and pupae) did not occur until larvae ingested 3 × 107 spores; this dose produced a mean of 1·8 × 107 spores in dead larvae and 3·6 × 107 and 4·6 × 107 spores in dead male and female pupae respectively.

A 2-YEAR STUDY OF THE EFFICACY OF BACILLUS THURINGIENSIS – CHITINASE COMBINATIONS IN SPRUCE BUDWORM (CHORISTONEURA FUMIFERANA) CONTROL

1976 ◽  
Vol 108 (3) ◽  
pp. 225-233 ◽  
Author(s):  
O. N. Morris
Keyword(s):  
Bacillus Thuringiensis ◽  
Direct Relationship ◽  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Residual Activity ◽  
Spruce Budworm ◽  
Time Deposit ◽  
Delayed Mortality ◽  
Carry Over

AbstractSpruce budworm infested balsam fir trees were aerially sprayed with Bacillus thuringiensis – chitinase combinations at the rate of 4 Billion International Units of B.t. and 18 mg of enzyme in 0.5 gal/acre. Larvae were peak third instar at spray time. Deposit rates ranged from 1.07 to 3.26 BIU/acre. Efficacy of the treatments was assessed in the year of treatment and carry-over effects were assessed 1 year later.Results in the year of treatment indicated that: (1) Residual activity of B. thuringiensis was drastically reduced after 15 days’ exposure to weathering. (2) Larval mortality alone is not a suitable criterion of efficacy. (3) Dipel and Dipel + chitinase (but not Thuricide 16B or Thuricide + chitinase) were highly effective in reducing budworm densities. (4) Thuricide + chitinase treatment resulted in significant foliage protection. The treatments inhibited feeding in the following order of efficiency: Thuricide + chitinase > Dipel + chitinase > Dipel alone > chitinase alone > Thuricide alone. (5) There was no direct relationship between larval mortality and foliage protection in any of the treatments, likely due to delayed mortality effects. (6) No direct relationship exists between viable spore deposits and deposit of active ingredient (IUs). (7) B.t. treatments retarded development of the spruce budworm and reduced pupal weights, oviposition rates, and egg viability.Assessment of the plots 1 year after spray showed that the treatments apparently gave no long term protection from defoliation, but this was likely due in part to mass invasion of the test plots by moths from immediately surrounding untreated areas.

Detrimental effects of feeding Pleistophora schubergi (Microsporida) to spruce budworm (Choristoneura fumiferana) naturally infected with Nosema fumiferanae

1978 ◽  
Vol 56 (4) ◽  
pp. 578-580 ◽  
Author(s):  
G. G. Wilson
Keyword(s):  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Spruce Budworm ◽  
Adult Longevity

Spores of the microsporidian Pleistophora schubergi Zwölfer were fed to spruce budworm, Choristoneura fumiferana (Clem.), naturally infected with Nosema fumiferanae (Thorn.). Larval mortality increased while female pupal weights, adult longevity, and fecundity were significantly reduced by feeding P. schubergi spores. High spore concentrations (5 × 108 spores) and inoculation as second-instar larvae produced the most detrimental effects.

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